
Watching basketball is an absolute blast, but it can be tough to follow all of the game’s action. The players are so fast that there’s no way for us, normal humans, to keep up with them. Thankfully we have recording technology that lets us rewatch their most glorious moves.
In previous articles, we looked at the rules which referees have to obey to trigger an instant replay and watch the action once again. Not only they are allowed to do that. There is a rule in place that provides head coaches of the team with one possibility to trigger instant replay and it’s called NBA Coach’s Challenge, or Challenge for short. It also is regulated to ensure the best game flow possible.
How Many Times Can a Coach Challenge a Foul?
Each team can challenge the referees only once during the entire game, no matter if their request has a successful outcome. Officials must be able to produce a piece of conclusive evidence in visual form, in order for the call on the field (or monitor) to get overturned – otherwise, the referee will uphold the original call.
What Can a Coach Challenge in the NBA?
As with everything in the NBA, there are rules concerning Coach’s Challenge. First, it’s of course the use of the Challenge. It can only be called during three events in the NBA games:
- Personal foul calls on the members of the team.
- Out-of-bounds violations call.
- Goaltending and basket interference violation calls.
Coaches can’t challenge non-calls and fouls charged to their opponent. They also can’t challenge flagrant fouls and violations such as double dribble, travelling, offensive three seconds, defensive three seconds or whether the defensive player committed a foul before the offensive player began his shooting motion.
When Can a Coach Challenge a Call?
According to the previous rule, in the final moments of the game, a team wasn’t able to utilize a Challenge to trigger an instant replay review of anything besides a foul. They couldn’t challenge an out-of-bounds infraction, or goaltending or basket interference violation call. They couldn’t use the challenge in the last two minutes or overtime period or the fourth period. The review of these events during these periods was to be exclusively handled by the on-court referees.
The refs can reverse whenever they want but coaches need a challenge? pic.twitter.com/H0z9YLPyBr
— ced (@nba_ced) November 14, 2021
The challenge rule was changed because the NBA came up with a different regulation, which stops the officials from calling for instant replay for out-of-bounds violations in the final moments of the game (the last two minutes of the fourth period or overtime period). Now, the coaches can challenge the referee anytime in the game. This implementation of this rule started with the 2021-202 season and it’s on a one-year trial basis.
How Can Coaches Challenge in the NBA?
The coaches can challenge in the following manner. The Challenge rule says that first, they have to call for a timeout unless there is one already. Then, they signal the referees with their fingers, showing the same sign that is used when an instant replay is in motion. They have to inform the same office that was asked for a timeout, or if a player asks for a timeout, they have to inform the officials which notifies the scorekeeper of a timeout.
During that same interaction, the coach has to point out which event is used to trigger replay review. The coach has to use his index finger and make a spinning motion.
If the opponent initiated the delay, the coach has 30 seconds to request an immediate replay review. If a compulsory timeout or a time-out by the opposing team has been called (depending on whether this is an advantage or negatively affected team), the jump-ball is tossed, or 30 seconds pass after notification, the challenging team could be charged with a delay-of-the-game foul.
Replay Review Process
When a Challenge is launched, the on-court crew chief will determine the ultimate result with personnel in the Replay Center playing a supporting role. When a Challenge is launched in the event of basket interference, goaltending or out-of-bounds ruling, the Replay Center will determine the ultimate result and give the final ruling.

There are two possibilities of resolving the Coach’s Challenge. Either call stands or it’s overturned. If the call stands, the challenging team is losing their timeout and if the call is overturned, the challenging team gets back their timeout. The play is resumed at the point of interruption.
When Was the Coaches Challenge Implemented in the NBA?
Everyone remembers when Kevin Durant famously stepped out of bounds, in a game between Golden State Warriors and Houston Rockets and the referee didn’t see it. The Warriors got a win from this situation and no one could do anything about it! The Coach’s Challenge was first implemented in the NBA G League and turned out to be successful.
A year since the out-of-bounds event, the NBA’s board of governors stated that the Coach’s Challenge will be a part of NBA rules for good from the start of the 2020-21 season. It is a fairly new rule and still needs some adjustments.